In this verse we have two plural words in 𝓟 (words and souls) that the 1830 compositor set in the singular (“hearken unto my word / arouse the faculties of your soul”). The 1981 LDS edition restored both of the plural readings. The Book of Mormon usually refers to a person’s speech by means of the plural words, but nonetheless the singular word is possible (as in Alma 7:26, “because of the exceeding diligence and heed which ye have given unto my word”). In 1 Nephi 16:24, Oliver Cowdery himself replaced “my words” with “my word”; here in Jacob 3:10, it was the 1830 compositor who made the mistake. In both places, the 1981 LDS edition restored the correct plural, “my words”. Although the 1908 RLDS edition is based on 𝓟, these two instances of the plural words have not been restored to the RLDS text. For further discussion regarding “my word(s)”, see 1 Nephi 16:24.
As far as the plural souls in “the faculties of your souls” is concerned, the overwhelming tendency of the Book of Mormon text is to use the plural souls when the text refers to more than one person. In fact, whenever we have “of soul(s)” (as a postmodifying prepositional phrase), we get only the plural souls (15 times):
Thus the critical text will maintain in Jacob 3:11 the plural souls in “the faculties of your souls”.
Summary: Follow in Jacob 3:11 the earliest textual source, the printer’s manuscript, for the two plurals words and souls (“hearken unto my words / arouse the faculties of your souls”).